Busway



Jul 20, 1965 Filed Feb. 2. 1961 E. "r. CARLSON 3,196,294

BUSWAY.

2 Sheets-Sheet l HRH 5. BER

mvam-o Elmer 7. 'zr wan/ E. T. CARLSON July 20, 1965 BUSWAY 2 Sheets-Shet 2 Filed Feb. 2, 1961 Elm/e) $2330 United States Patent 3,196,294 BUSWAY Elmer T. Carlson, Center Valley, Pa., assignor, by mesne assignments, to Cutler-Hammer, Inc., Milwaukee, Wis., a corporation of Delaware Filed Feb. 2, 1961, Ser. No. 86,630 Claims. (Cl. 307-147) The present invention relates to busways of the type which are used to carry electric power in industrial plants, buildings and the like.

A purpose of the invention is to provide busways which can conveniently have a large number of conductors so as to make available a variety of different characters of electric power with respect to alternating or direct current, different voltages, different frequencies of alternating current, and the like.

A purpose of the invention is to make a busway construction more adaptable to the use of different numbers and different thicknesses of busbars.

A further purpose is to permit more adequate support of busbars at a point at which plug-in is to take place.

A further purpose is to make the insertion and removal of busbars easier.

A further purpose is to make busways more resistant to shock, impact, explosion and the like.

A further purpose is to obtain an auxiliary source of current by providing high voltage busbars and also auxiliary busbars in the same busway system, to make plugin connection to both high voltage and auxiliary busbars at a particular joint, and to connect a transformer at one side to the plug-in contacts connected to the high voltage busbars and at the other side of the plug-in contacts connected to the auxiliary busbars.

Further purposes appear in the specification and in the claims.

In the drawings I have chosen to illustrate a few only of the numerous embodiments in which my invention may appear, selecting the forms shown from the standpoints of convenience in illustration, satisfactory operation and clear demonstration of the principles involved.

FIGURE 1 is a fragmentary top plan view of the busway of the invention with the housing broken away to show the interior.

FIGURE 2 is a section on the line 22 of FIGURE 1 showing a plug-in device connected to the busway of FIGURE 1 with the housing broken away but indicated by dot-and-dash lines.

FIGURE 3 is a section on the line 33 of FIGURE 1.

FIGURE 4 is a perspective of the insulating supports used in the busway of FIGURES 1 to 3.

FIGURE 5 is a fragmentary perspective of a variant form of busway in accordance with the invention.

FIGURE 6 illustrates a circuit diagram of a busway of the invention employing transformers.

There is considerable need in the art, particularly by laboratories and diversified industrial plants, for busways having a large number of conductors so that electric current of various types can be supplied. For example, in a particular installation there may be a desire for direct current, for an alternating current three-phase, three-wire circuit at say 480 volts, 60 cycles, for an alternating current three-phase, four-wire circuit at 120/208 volts, 60 cycles, and for an alternating current three-phase, fourwire circuit at 120/208 volts, 400 cycles per second. Prior art busways have been designed particularly with a view to the employment of relatively large busbars and they do not lend themselves readily to production of variant constructions having numerous busbars designed to meet the particular requirements, and having in some cases variant dimensions for diiferent busbars.

The present invention admirably meets this requirement with relative ease to insert a large number of busbars and busbars of different thicknesses.

Some of the prior art constructions have not provided adequate support for the busbars at the point of plug-in. One of the advantages of the present invention is that support of the busbars is provided on both sides of the point of plug-in and not merely cantilever support at one side.

The bus duct of the invention is extremely sturdy and resistant to shock and impact in handling and impact due to explosions and the like in service.

The invention contemplates that a plug-in may be used to connect auxiliary busbars through a transformer to main busbars, so that both high voltage and auxiliary voltage can be taken off at another plug-in on the busway.

Considering now the drawings in detail, I illustrate a bus duct having a housing 20 which suitably surrounds the conductors and is provided with openings at plug-in points suitable covered by slides, as shown in Carlson and Constantine US. Patents Nos. 2,786,908; 2,825,775; 2,879,319; 2,903,503; 2,907,839 and Carlson US. Patent No. 2,955,147.

Through the interior of the busway there extends longitudinally a plurality of conductors or busbars 21 of which 13 are shown, merely to suggest that a relatively large number may be used as desired. Each of the conductors has an insulating wrapping 22 surrounding it, except that the insulating wrapping is removed at areas 23 where plug-in is to be accomplished to plug connectors 24 mounted in insulating bushings 25 of a plug connector device 26, as well known.

It will be evident that if desired the insulation can be omitted on alternate busbars (not shown).

At locations where plug connection is to be made, the bus duct housing has mounted at opposite sides thereof brackets 27, each of which is suitably of inverted U form having a base of the U, 27, sides of the U, 28, and diverging feet 29 which are secured to the housing 20 as by screws 30 extending through openings 31 in the feet 29.

At each side of the arms 28 of the U, beneath the busbars, extending across from one bracket 27 to another, is a strip 32 of insulation board, suitably fiberglass base polyester insulation board well known in the art, anchored to the bracket at each end by a screw 33. At the opposite side of the busbars from the strips 32, extend similar insulating strips 34, suitably on edge and held to the sides of the Us of the brackets at the end by screws 34'.

It will thus be evident that the precise spacing of the strips 32 and 34 at the middle can be determined by cutting a slot 35 in the upper strip 34, as shown in FIGURE 4, which will extend uniformly from side to side, the strips 32 and 34 touching at the ends, and if it is expected that some busbars will be thicker than others, the slot 35- may have a wider portion 35' as shown in FIGURE 5 to receive the extra thickness of busbars. Thus, it will be evident that a wide selection of diiferent busbars can be used and the support can readily be adjusted to this.

U-shaped insulating sheets 36 are provided, extending up between the busbars at the locations of the plug connectors, as best seen in FIGURE 2, the bases of the Us desirably being secured as by cementing to the housing at 37.

Great versatility of the busway is obtained as shown in FIGURE 6. Here the busway includes high voltage A.C. busbars 21 and lower voltage auxiliary busbars 21'. At a suitable point a plug-in device 38 is connected to the busbars as in FIGURE 2. Contacts 40 and 41 are connected to one phase of the high voltage busbars 21, and also connected to the primary 42 of transformer 43. The

3 secondary 44 of the transformer is connected to plug contacts 45 and 46, connected'to auxiliary busbars 21.

Then at any other suitable point along the busway plug-in device 47 can be connected to take off main voltage A.C. through leads 48, 50 and 51, and auxiliary voltage through lead 52 and 53.

At any desired points on the busway, busbars 21 can be interrupted, and plug-in at another point of a diiferent transformer 43 to obtain a different auxiliary voltage can be made.

In operation, the device ofFIGURES 1 to 5 can be assembled readily with different busbars as desired. Then the plug-in transformer 43 of FIGURE 6 can be inserted as desired to obtain the correct auxiliary voltage.

In view of my invention and disclosure, variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of my invention without copying the structure shown, and I, therefore, claim all such insofar as they fall within the reasonable spirit and scope of my claims.

Having thus described my invention What I claim as new and desire to secure by Letters Patent is:

1. In a busway, a plurality of busbars, a housing surrounding said busbars, pairs of substantially U-shaped brackets secured to an inner wall of said housing in alined, spaced apart relation transversely of the length of said housing, insulating strip members secured at opposite ends on both pairs of the alined legs of said pairs of brackets and supporting on their edges said busbars in spaced apart relation between said brackets.

Z. A busway according to claim 1 wherein there are insulating strips secured to said bracket legs on opposite transversely of the length of said busway in areas underlying and encompassing the area of said openings, insulating strip members secured at opposite ends on both pairs of the alined legs of said pairs of brackets above and below said busbars and supporting the latter in spaced apart relation between said brackets, and U-shaped insulating members having their bights secured to the inner wall of said housing in areas including each opening and having their legs extending partially around said busbars to provide insulating barriers between said busbars in the regions where plug-in devices make contact with said busbars.

5. In a busway, high voltage busbars and auxiliary busbars extending side by side, a plug-in device making contact with the respective busbars at a particular point,

' and transformer means mounted in said plug-in device and sides of said busbars to secure the same in place in said 7 connected at one side to high voltage busbars and at the other side to auxiliary busbars through said plug-in device to provide said auxiliary busbars with an auxiliary voltage different from said high voltage.

References Cited by the Examiner UNITED STATES PATENTS OTHER REFERENCES Standard Handbook for Electrical Engineers, 7th ed., sec. 15-61 and FIGURE 18, page 1410.

LLOYD MCCOLLUM, Primary Examiner.

ORIS L. RADER, Examiner. 

1. IN A BUSWAY, A PLURALITY OF BUSBARS, A HOUSING SURROUNDING SAID BUSBARS, PAIRS OF SUBSTANTIALLY U-SHAPED BRACKETS SECURED TO AN INNER WALL OF SAID HOUSING IN ALINED, SPACED APART RELATION TRANSVERSELY OF THE LENGTH OF SAID HOUSING, INSULATING STRIP MEMBERS SECURED AT OPPOSITE ENDS ON BOTH PAIRS OF THE ALINED LEGS OF SAID PAIRS OF BRACKETS AND SUPPORTING ON THEIR EDGES SAID BUSBARS IN SPACED APART RELATION BETWEEN SAID BRACKETS. 